Vat dyestuffs of the benzanthrone series



I Patented Oct. 13, 1 9 31h UNITED AT ARTHUR LI j'TTBINGHAUSAND HUGO WQLFR'JOF itmivm mm, 'nnp nEnvaIoirNER-Es:

HEIMER, or LuDW GsHAFEN-OMTHERHIN GERMANY; ASSIGNOBS [ISOGENERALL VANILIVNE WORKS, 11m, 01* NEW YORK, N. 2,,nconrorturrouO ELAWAR V j n VAT DYESTUFFS or rHE'BENZAnT RONE-SERIE Na Drawing. Application filed October 25, 1926,"Ser1 a 1 ml,144,1 7o, and nils tz rialia mew; 192e,"

In the S. Patent No. f1,505,912, new vat dyestuffs are described which are 7 derived from oxidized dibenzanthrone and which con- -We have now found that specifically those derivatives of oxidized dibenzanthrones which probably correspond "to the general 7 g I g or i a afreddish-brown precipitate isfiltered ofl'."

formula 4 3 i 1 (in which Halmeansa halogen atom, R 1a dicates a hydrogen atom or an alkyl group and X means a hydrogen or halogen atom) and'which are obtainable by acting on 6 agent and, if R is an 'alkyl group, subsequently alkylating the reaction product, are-par ticularly valuable. While dyeings produced with 6-halogen or 6.6edihalogen-dihydroxy- V dibenzanthrones are not "entirely fast, the" products are excellently suitable as interme diary products, whereas the derivatives of 6-halogenor 6.6'-dihalogenedihydroxy di benzanthrones in which R is an alkyl' group are remarkable for the-brilliant greenshades of their dyeings and their excellent fastness.

The said coloring matters can be obtained for example by acting on 6v-halogen-2.2-dibenzanthronyl or on 6,6 -dihalogen-22-dibenzanthronyl with av strongly oxidizing coni f densing agent in the manner described in the U. S. Patent No.1,564,423 and'subsequently throne so obtained by treating with alkylatintroducing alkyl groups into the 6-halogen-or 6;6-dihalogen dihydroxy-dibenzaning'agents such for example as dialkylsul- I fates or alkyl esters of toluene sulfonic acid.

. The following example will further illustrate how our invention may be carried out in practice, but the invention is notlimited to this example. The parts are by weight;

A suspension of 30 parts of manganese di- 'oxid in 150 parts of concentrated sulfuric f parts i of-concent-rated sulfuric acid at a' temper'aturenot higher than 10", C. linlthegcourse' ofan hour,while-stirring; Thereupon the a mixture isfs'tirred for about 2hours atibetween-6 and S CQandHthen pouredfinto w'ate r; {The i oxidation product .of f6.e.' gdi. chlor-dlbenz'a'nthrone separated in i the, form brown: color. By? treating it with reducing agent'ssuch as {sodium bisulfite and the like, halogenor 6.6"- dihalogen-QQ; d1benzan-" thronyl with a stronglyfoxidizing condensing color is changed to greenish blue; v The reduction product to {obtained which when treated w th; oxidizing agents is again converted intothe'recldish brownfsubstance, dis

effected by other oxidizing agents.

he oxidation desciibed'abeyet h alsofbe ii i i g e insoluble in' data allia'lisj an'd dissolves inpconcentr ated sulfuric ajeid with areddish an k i e'hrdr ie fi el .1 I

i The same oxidation- "roduc gas described above can also be obtained by starting from -d'ichlordifbenz anthrone g and oxidizing it for example'by meansofmanganese dioxid in o I concentrated sulfuric acid:

Inorder to introduce alkyl groups, for intrichlorbenzene, 10. parts =of1soda ash and 10 parts of p-toluenesulfonic acidmethyl ester,

' stance methyl radicals,- l 0 partsfofth'e oxida- 1 tionproduct'describedfabove are boiled for 3 V hoursunder a-reflux coolerwith lbQ'parts of g V The-mixture isiallowed to'cool and the precipitatethen sucked off. Theolid residue is freed fromtriehlor-benzeneinthe usual man- Q .lization or by dissolving it in concentrated" sulfuric-acid and precipitatin'glfby means of less concentratedsulfuricfacidl The vat dye- I stuflilso obtained forms a .darkl'bluish green v1oo ner and dried; It may be purified by crystalpowder dissolving concentrated sulfuric acid with a reddish violet, in fuming sulfuric acid with a reddish brown color. It is insoluble in water and hot dilute alkalis. With an alkaline hydrosulfite solution it forms a blue 5 vat, from which cotton is dyedblue shades which after washing turn into a very fast yellowish green by the oxidizing action'of the air. The 6.6-dichlor-dimethoxy-dibenzanthrone is converted into a coloring matter dyeing more bluish shades when heated for an hour to between 70 and 75 C. with about 30 times its weight of sulfuric acid of 96 per cent strength. By this property it is diiferentiated from the chlorination product of dimethoxy-dibenzanthrone described in the U. S. Patent 1,505,912, which when subjected to the same treatment is converted into a coloring matter dyeing more yellowish shade than the initial material. The 6 -halogenor 6.6-dihalogen-2.2-'dibenzanthronyls or -dibenzanthrones may be obtained for example bycondensing mixtures of 6-halogen-benzanthrone with 2-halogenjbenzanthrone or 2.6-dihalogen-benzanthrone 2 by means of alkaline condensing agents under mild or strong conditions.

What we claim is: 1. As a new article of manufacture, 6.6- dichlor-BZ2.Bz2'-dimethoxy-dibenzanthrone which dissolves in concentrated sulfuric acid with a reddish violet, in fuming sulfuric acid with a reddish brown color, is insoluble in water and hot dilute alkalis, forms a blue vat with an alkaline hydrosulfite v solution, from which cotton is dyed very. fast yellowish green shades, and which when heated for an hour to between 70 and 75 C. with about 30 times its weight of nearly concentrated sulfuric acid, is converted into a coloring matter dyeing more bluish shades.

2. Aprocess for the production of 6.6- dichlor dimethoxy dibenzanthrone which comprises acting on a solution of 6.6-dichlor- 2.2'-dibenzanthronyl in concentrated sulfuric acid with manganese dioxid and subsequently methylating the reaction product. 3. As new articlesof manufacture coloring I matters of the dibenzanthrone series which probably correspond to the general formula R0 OR ARTHUR LUTTRINGHAUS. HUGO WOLFF. HEINRICH NERESHEIMER. 

